[jira] Commented: (MAPREDUCE-1648) Use rolling to limit tasklogs

["Hadoop QA (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/MAPREDUCE-1648?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13000140#comment-13000140 ] 

Hadoop QA commented on MAPREDUCE-1648:
--------------------------------------

-1 overall.  Here are the results of testing the latest attachment 
  http://issues.apache.org/jira/secure/attachment/12443921/MAPREDUCE-1648-v4.patch
  against trunk revision 1075216.

    +1 @author.  The patch does not contain any @author tags.

    +1 tests included.  The patch appears to include 3 new or modified tests.

    -1 patch.  The patch command could not apply the patch.

Console output: https://hudson.apache.org/hudson/job/PreCommit-MAPREDUCE-Build/85//console

This message is automatically generated.

> Use rolling to limit tasklogs
> -----------------------------
>
>                 Key: MAPREDUCE-1648
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-1648
>             Project: Hadoop Map/Reduce
>          Issue Type: Improvement
>          Components: tasktracker
>            Reporter: Guilin Sun
>              Labels: logging
>         Attachments: MAPREDUCE-1648-v4.patch, mapreduce-1648-design.pdf, syslog-baidu-v2.patch
>
>   Original Estimate: 0h
>  Remaining Estimate: 0h
>
> There are at least two types of task-logs: syslog and stdlog
> Task-Jvm outputs syslog by log4j with TaskLogAppender, TaskLogAppender looks just like "tail -c", it stores last N byte/line logs in memory(via queue), and do real output only if all logs is commit and Appender is going to close.
> The common problem of TaskLogAppender and 'tail -c'  is keep everything in memory and user can't see any log output while task is in progress.
> So I'm going to try RollingFileAppender  instead of  TaskLogAppender, use MaxFileSize&MaxBackupIndex to limit log file size.
> RollingFileAppender is also suitable for stdout/stderr, just redirect stdout/stderr to log4j via LoggingOutputStream, no client code have to be changed, and RollingFileAppender seems better than 'tail -c' too.

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